My seat in particular is a 17" model (I'm 6'2 220) and it fits perfect, though I could have gone with an 18 and still had space.

I used jegs universal 90* brackets, and mounted the seat close to the stock location with some M10x1.25 bolts and locknuts. I had to drill holes for the bolts and the submarine strap.

Submarine belt location, just slightly behind shoulderline (must be behind to be legal)

More finished pics coming shortly as I finish installing the seat.

The seat itself, bare

Test fit with harness and no cover

Test fit with harness and no cover

Finished with harness adjusted and cover on!

Not a bad way to add safety and lose 40 pounds. Next step is getting the backbrace mounted to the rollbar. More to come. Took a short trip to break in 3.91s and this seat is snug but damn comfy! I was blown away by how well it fits me, the padding in the cover is awesome.